Research On Spectral Reconstruction Technology For Chinese Painting

With the development of digital imaging technology,people are increasingly demanding the accuracy of image color reproduction.But now,the Spectral-based color reproduction technology has been deeply researched in color science area because of that could deal with the metamerism.Meanwhile,the multi-spectral imaging system plays an important role in the Spectral-based color reproduction technology,especially about the color reproduction of Dunhuang Murals and oil paintings.However,the Chinese painting which the pigments and the paper chosen are not similar with Dunhuang Murals and oil paintings that was not gotten researched by using the multi-spectral imaging system.What is more,the color could be rendered and changed during the process of creating the Chinese paintings.So in order to deal with these problems,making the Chinese painting pigment color cards by using the 24 color Marley Chinese painting pigments to form a database of the Chinese painting colors was proposed in this paper.The process of making Chinese color cards was that match different pigments according to the ratio of 1:1 and 1:2 ratio and chose the raw rice paper which was similar with the Chinese paintings as the carrier.Meanwhile,the relative training sample selection methods could be used to chose the suitable samples from this database of Chinese painting pigments color cards.And the deeply researched about Chinese paintings was made based on the muti-spectral imaging technology.The multi-spectral image acquisition system by using the Cannon EOS 5D digital camera with the green color filter was constructed in this paper,which could have six channels to acquire spectral imaging,and the 2750 K color temperature would be selected as the illumination source.What is more,the optimum shooting conditions was found by repeated experiment,which could promise the imaging spectral information to be gotten accurately and achieve the aim of reconstructing color information of Chinese paintings.The experiment results showed that the proposed method could be effectively got the spectral information of Chinese painting pigment color cards.For the problem of spectral reflectance reconstruction algorithm of Chinese painting pigment color cards,the Pseudo-inverse algorithm and PCA were mainly used in this paper,meanwhile,when the training samples were selected,the 24 colorchecker cards was chosen the contrast of the Chinese painting pigment color cards.The contrastive experiment results showed the Chinese painting pigment color cards as training samples to reconstruct the spectral of Chinese painting colors was better than the 24 color checker cards.And the reconstruction accuracy of PCA was better than the Pseudo-inverse algorithm.It was mainly reflected in the average color difference calculated by PCA for spectral reconstruction is reduced by 0.9874 compared with pseudo-inverse method,and the standard deviation is reduced by0.0233 and the maximum color difference is reduced by 0.3212.At the same time,the mean square error was reduced by 0.0122,the standard deviation was reduced by0.0012,and the maximum mean square error was reduced by 0.0247.For the problem of reproduction of the Chinese painting colors,the different illumination source which were the D65 light source and the 2750 K color temperature light source were used to render and evaluate the Chinese painting and the normal image.The experiment results showed that the selected lighting source could not have an effect on the color reproduction of the artwork,but the selection of training samples could make the influence on it,which could prove “the same color and the same spectral” color reproduction could be realized.This is because that the pigment of Chinese painting is different from the normal image,which lead to larger color difference when the color information of normal image was reconstructed by using the Chinese painting pigment color cards.